ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Summary of Amounts Reclassification from AOCI to Net Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of tax	$ (31)	$ (406)	$ 31	$ (373)
Income tax expense (benefit)	(11)	(22)	56	(62)
Net income (loss) attributable to Baxter stockholders	91	(314)	217	(277)
Other (income) expense, net	0	24	3	33
Costs of sales	(1,819)	(1,663)	(3,583)	(3,192)
Amounts reclassified from AOCI
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income (loss) attributable to Baxter stockholders	2	1	(109)	0
Amounts reclassified from AOCI | CTA
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of tax	0		(126)
Income tax expense (benefit)	0		0
Net income (loss) attributable to Baxter stockholders	0		(126)
Amounts reclassified from AOCI | Pension and OPEB items
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income (loss) from discontinued operations, net of tax	0		(14)
Income tax expense (benefit)	(1)	0	(2)	1
Net income (loss) attributable to Baxter stockholders	2		15
Other (income) expense, net	3	1	6	3
Income (loss), before tax	3	1	20	2
Less: Tax effect on pension settlement from Kidney Care separation	0		(3)
Amounts reclassified from AOCI | Gains (losses) on hedging activities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income tax expense (benefit)	0	1	(1)	1
Net income (loss) attributable to Baxter stockholders	0	0	2	(2)
Income (loss), before tax	0	(1)	3	(3)
Amounts reclassified from AOCI | Gains (losses) on hedging activities | Foreign exchange contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net	2		6
Costs of sales		3		5
Amounts reclassified from AOCI | Gains (losses) on hedging activities | Interest rate contracts
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense, net		(2)		(3)
Costs of sales	$ (2)		$ (3)
Amounts reclassified from AOCI | Gains (losses) on hedging activities | Fair value hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other (income) expense, net		$ (2)		$ (5)